Find the equation for the parabola that has its vertex at the origin and the focal point is 314 units above the directrix. equation is

This one has a focal length of 314/2 = 157

and it i concave up since the directrix is below the vertex.

so       $$a=157$$

$$\\x^2=4ay\\\\ x^2=4*157y\\\\ x^2=628y$$